China's First Independent Cobalt Deposit and its Metallogenic Mechanism:Evidence from Fluid Inclusions and Isotopic Geochemistry

The Tuolugou cobalt deposit is the first independent large-scale Co- and Au-bearing deposit discovered in northwestern China. It is located in the eastern Kunlun orogenic belt in Qinghai Province, and occurs conformably in low-grade metamorphic volcano-sedimentary rock series with well-developed Na-rich hydrothermal sedimentary rocks and typical hydrothermal sedimentary ore fabrics. Fluid inclusions and isotopic geochemistry studies suggest that cobalt mineralizing fluid is dominated by NaCI-H20 system, accompanied by NaCI-CO2-H20-N2 system responsible for gold mineralization. Massive, banded and disseminated pyrite ores have similar compositions of He and Ar isotopes from the mineralizing fluid, with 3He/4He range between 0.10 to 0.31Ra （averaging 0.21Ra）, and 4~Ar/36Ar between 302 and 569 （averaging 373）, which reflects that Co mineralizing fluids derived dominantly from meteoric water deeply circulating. ~34S values of pyrite approaches to zero （~34S ranging from -4.5%o to ＋1.5%o, centering around -1.8%o to -0.2%o）, reflecting its deep source. Ore lead is characterized by distinctly high radiogenesis, with 2~6pb/2~4pb〉19.279, 2~7pb/2~4pb〉15.691 and 2~spb/2~4pb〉39.627, and its values show an increase trend from country rocks, regional Paleozoic volcanic rocks to ores. This may have suggested that high radiogentic ore Pb derived mainly from country rocks by leaching meteoric water-dominated hydrothermal fluid during its circulation at depth. Cobalt occurs mainly in sulfide phase （such as pyrite）, but cobalt enrichment, and presence and increasing contents of Co-bearing minerals have a positive correlation with metamorphic degree. The Tuolugou deposit and other typical strata-bound Co-Cu-Au deposits have striking similarities in the geological features and metallogenic pattern of primary cobalt. All of them are syngenetic hydrothermal exhalative sedimentation in origin.

Cobalt Deposits of China: Classification, Distribution and Major Advances

The important strategic metal cobalt has diverse uses and the majority of world cobalt deposits have been found in China. The deposits can be classified into four types, i.e., magmatic Ni-Cu-Co sulfide deposits, hydrothermal and volcanogenic cobalt polymetallic deposits, strata-bound Cu-Co deposits hosted by sedimentary rocks and lateritic Ni-Co deposits, of which the former two types are the most important. There are six principal metallogenic epochs and seven important metallogenic belts according to their distribution and tectonic position. Although cobalt generally occurs in nickel-copper, copper and iron deposits as an associated metal, great developments in exploration for independent cobalt deposits have happened in China, and, in recent years, many independent deposits with different elementary assemblages and different genetic types have been discovered in the eastern part of the northern margin of the North China platform, the Central Orogenic Belt of China, western Jiangxi and northeastern Hunan. In addition, it is inferred that the Kunlun-Qinling Orogenic Belt has great potential for further exploration of new types of independent cobalt deposits.

Newly Discovered Native Gold and Bismuth in the Cihai Iron-Cobalt Deposit, Eastern Tianshan, Northwest China

The Cihai iron-cobalt deposit is located in the southern part of the eastern Tianshan iron- polymetallic metallogenic belt. Anomalous native gold and bismuth have been newly identified in Cinan mining section of the Cihai deposit. Ore formation in the deposit can be divided into three stages based on geological and petrographical observations： （I） skarn, with the main mineral assemblage being garnet-pyroxene-magnetite; （II） retrograde alteration, forming the main iron ores and including massive magnetite, native gold, native bismuth, and cobalt-bearing minerals, with the main mineral assemblage being ilvaite-magnetite-native gold-native bismuth; and （III） quartz-calcite- sulfide assemblage that contains quartz, calcite, pyrrhotite, cobaltite, and safflorite. Native gold mainly coexists with native bismuth, and they are paragenetically related. The temperature of initial skarn formation was higher than 340~C, and then subsequently decreased to -312~C and ~266~C. The temperature of the hydrothermal fluid during the iron ore depositional event was higher than the melting point of native bismuth （271~C）, and native bismuth melt scavenged gold in the hydrothermal fluid, forming a Bi-Au melt. As the temperature decreased, the Bi-Au melt was decomposed into native gold and native bismuth. The native gold and native bismuth identified during this study can provide a scientific basis for prospecting and exploration for both gold- and bismuth-bearing deposits in the Cihai mining area. The gold mineralization in Cihai is a part of the Early Permian Cu-Ni-Au-Fe polymetallic ore-forming event, and its discovery has implications for the resource potential of other iron skarn deposits in the eastern Tianshan.

Cobalt Deposits in the Central China Orogenic Belt

Cobalt mostly occurs as an associated metal in Cu-Ni sulphide deposits, skarn Fe-Cu-Pb-Zn deposits and volcanic-hosted massive sulphide (VHMS) or sedex deposits. There are different types of cobalt deposits in the Central China orogenic belt. In the Tamu-Kalangu Mississippi-valley type Pb-Zn deposits, many cobalt-nickel sulphide minerals were found. The cobalt content of the ore is 0.064%-0.46% in sedex-type Kendekeke Fe-Pb-Zn-Au deposits, and cobalt sulphide veins with Co contents of 4%-9% have also been found. About 28000 tons of cobalt reserves were delineated in the Dur'ngoi Cu-Co-Zn deposit of VHMS type in the A'nyemaqên Mountains. It is considered that the exploration potential for cobalt is attractive in this district, especially in sedex-type deposits and Co-rich sulphide veins in sedex-type Fe, Cu and Pb-Zn deposits and their surroundings.

Tribological properties of cobalt-based alloy coating with different cobalt contents by electro-spark deposition

The cobalt-based alloy coating with different Co contents was deposited on 45 steel by electro-spark deposition with the self-made electrode. The coating has a compact and uniform microstructure with low porosity and no visible microcracks. When Co content increases grad- ually, oxygen content of coating samples 1-5 decreases first and then increases in the range of 2.52 wt%-3.05 wt%; sample 3 has the lowest oxygen content of 2.52 %. Mi- crohardness of the coating is improved remarkably com- pared with the substrate （HV 230.18）. With Co content increasing, microhardness of the coating samples 1-5 first rises slightly and then declines rapidly in the range of HV 580.61-1052.33. Sample 3 gets the maximum of HV 1052.33, which is about 4.6 times that of the substrate. The coating presents excellent wear resistance, which first increases and then decreases when Co content increases. Sample 3 shows the best wear resistance of about 6.4 times that of the substrate. Main wear mechanism of the coating is abrasive wear and fatigue wear, along with oxidation wear under high speed or heavy load conditions.

东昆仑造山带岩浆镍钴硫化物矿床形成构造背景探讨

【研究目的】青海省夏日哈木超大型岩浆镍钴硫化物矿床是世界范围内造山带背景发现的最大岩浆镍钴硫化物矿床。此外在东昆仑造山带夏日哈木外围还发现了石头坑德等岩浆镍钴硫化物矿床,初步显示东昆仑造山带良好的镍钴硫化物矿床形成条件和巨大的找矿潜力。【研究方法】通过野外地质调查,室内开展岩石学、矿相学、主微量元素分析、同位素地球化学等。【研究结果】精确锆石U-Pb测年发现,东昆仑造山带夏日哈木等含矿镁铁—超镁铁质岩体基本形成于425~330 Ma,沿柴达木盆地南缘昆北断裂和昆中断裂自西向东依次展布。含矿岩体的岩性主要为辉石橄榄岩、辉石岩、二辉橄榄岩、纯橄岩等,其SiO_(2)含量31.52%~53.31%,MgO含量7.5%~39.03%,Al_(2)O_(3)含量0.1%~16.01%,CaO含量0.23%~13.85%,MgO与SiO_(2)、Al_(2)O_(3)、Na_(2)O、K2O均呈负相关关系。稀土总量介于6.36×10^(-6)~81.5×10^(-6),平均为29.92×10^(-6),LREE/HREE平均值为5.34,(La/Sm)N、(La/Yb)N、(Sm/Nd)N、(Gd/Yb)N平均值分别为2.58、5.99、0.76、1.78,轻重稀土分异程度较高。含矿超镁铁质岩普遍具有较为一致的微量元素分布曲线,且与镁铁质岩石表现特征类似,亏损高场强元素Ta、Nb、Ti、P等,而相对富集大离子亲石元素Rb、Th、U等。Sr、Nd同位素研究指示夏日哈木、石头坑德等岩体岩浆源区来源于软流圈地幔,同时δ^(34)S均表现出较高的正值,揭示地壳物质同化混染是形成岩浆镍钴硫化物矿床的关键因素。【结论】结合区域最新构造演化认识,认为东昆仑夏日哈木等超大型岩浆镍钴硫化物矿床是伴随古特提斯裂解岩浆活动的成矿表现。该认识对丰富造山带内岩浆镍钴硫化物矿床成矿理论研究、拓展岩浆镍钴矿床找矿空间与潜力、支撑引领区域找矿实践实现新突破,均具有重要的研究价值和意义。

浅谈湿法冶炼锌中上清液净化沉钴方法与应用

本文主要介绍了湿法炼锌硫酸锌溶液中钴的沉淀方法、工艺及生产现状,对传统的沉钴方法及工艺存在的优势、缺陷进行了分析,综述了近几年来沉钴技术上的研究进展及取得的进步,有助于提高企业技术水平及经济效益。

山东莱芜垂阳矽卡岩型铁矿尾矿中关键金属钴综合利用评价探讨

1研究目的钴是高温合金、电池材料、防腐材料、磁性材料等重要原料,广泛应用于航空航天、电子电器、机械制造、汽车、化工农业、陶瓷等领域,在国民经济和社会发展中具有特殊的意义。特别是从移动电子设备,到新能源汽车的动力电池,再到电网储能,钴作为锂电池正极材料——钴酸锂的重要组成,都是不可或缺。因此,钴被世界上众多国家列为21世纪重要的关键战略资源(Gulley et al.,2018)。现今我国是世界上最大的钴资源进口国(95%依靠进口)和消费国(US Geological Survey,2018),而且钴资源紧缺,保障程度低(蒋少涌等,2019;许德如等,2019)。

河北某邯邢式铁矿矿石特征及钴的赋存状态研究

采用化学分析、光学显微镜、X射线衍射分析、电子探针以及矿物自动分析系统(AMICS)等手段对矿石进行全面研究,重点关注其化学组成、矿物组成、嵌布特征、矿物粒度以及有用元素钴的赋存状态等工艺矿物学特征。研究结果表明,该矿石中磁性铁的含量占比达到94.23%,主要以磁铁矿为主要回收矿物。而钴的品位为0.014%,硫的品位为1.89%,在回收利用铁资源的同时,可进一步回收硫钴元素。矿石中的主要金属矿物包括磁铁矿、黄铁矿以及少量的铜矿物,非金属矿物主要包括蛇纹石、金云母和碳酸盐矿物等。矿石的结构形式主要为半自形-它形晶粒状结构、交代结构以及包含结构等;构造以块状构造和浸染状构造为主。当矿石破碎至-2mm时,磁铁矿和黄铁矿的粒度较粗。在矿石中并未发现钴的独立矿物存在,钴是以类质同象的形式赋存于磁铁矿、黄铁矿以及褐铁矿中。通过采用适当的选矿工艺,可以获得硫钴精矿,从而进一步富集和回收钴元素。这些研究结果为该矿的综合利用提供了重要的参考和依据。

全球沉积–变沉积型钴成矿规律及其对宁夏钴矿找矿研究的启示

钴是全球战略性关键金属矿产,对国民经济建设和新兴产业发展具有重要意义。宁夏北山钴矿被认为是具有多期热液叠加改造的沉积–变沉积型钴矿床,但其成矿时代和构造背景以及钴的来源、赋存状态和迁移富集机制等研究还比较薄弱。为探讨上述问题并启示宁夏北山钴矿找矿研究,笔者系统总结了全球沉积–变沉积型钴成矿规律,其成矿时代主要集中在古元古代—新元古代,空间上主要分布于中非赞比亚–刚果金、美国爱达荷、芬兰和中国等地,与全球超大陆聚合与裂解旋回、全球大氧化和极端气候等重大地质事件有密切关系。基于上述研究,笔者认为宁夏北山钴矿研究应在成矿年代学、重大地质事件与成矿关系、含矿地层地球化学特征、物源属性及其成矿构造背景、数据驱动的钴成矿预测等方面开展深入和详细的研究,支撑服务战略性关键金属矿产找矿行动。

新疆某铜钴矿矿石基因特性及其对磨选的影响

为查明新疆某铜钴矿的矿石基因特性,为后续选矿工艺设计提供理论指导,本文利用电子探针、矿物自动分析系统及X射线衍射仪等对该矿床矿石的基因特性进行了研究。研究结果表明:矿石中的金属矿物主要为黄铜矿、毒砂-辉砷钴矿系列矿物和黄铁矿;矿石中的Cu赋存于黄铜矿中,93.30%的Co赋存于毒砂-辉砷钴矿系列矿物中,其余6.70%赋存于黄铁矿中,黄铜矿和毒砂-辉砷钴矿系列矿物粒度均以中细粒为主(0.010~0.300 mm),在-0.074 mm占70%的磨矿细度下,目的矿物均有一定的解离,但仍有部分为连生体,为降低磨矿成本、保证回收率和精矿品质,建议采用在磨矿细度下进行全硫化物浮选,然后粗精矿再磨后进行Cu、Co分离的选矿工艺;Co的赋存状态特征指示,浮选过程中As与Co的走向相同,会造成钴精矿中As超标,且由于毒砂-辉砷钴矿系列矿物与黄铜矿嵌布关系密切,两者很难达到完全单体解离,易造成铜精矿中As也偏高。本文通过研究新疆某铜钴矿的矿石基因特性,指出了影响磨选的矿物学因素,对后续矿物加工具有理论指导意义。

东昆仑驼路沟钴金矿床中黄铁矿的结构和成分特征及其对钴成矿作用的启示

驼路沟钴金矿床是我国少见的大型热液型矿床。为了深入认识该矿床(含)钴成矿过程,选取驼路沟矿床中的富钴黄铁矿为研究对象,通过岩相学、矿物学、微量元素特征和S同位素组成分析,确定黄铁矿结构、成矿流体特征、演化过程及成矿物质来源,进而揭示详细的成矿过程,以及黄铁矿对钴成矿的指示作用。研究表明,驼路沟含钴黄铁矿可分成三部分:晶型较好、偶见孔隙的黄铁矿核部;具有震荡环带,与硫镍钴矿、辉砷镍矿共生的黄铁矿幔部;晶型较好的黄铁矿边部。其中,黄铁矿核部富集Co、Ni等元素,幔部富集Co、Ni、As等元素,边部具有较高的As、Se含量和稍高的Au含量。三者对比显示,核部Co含量最高,幔部As含量最高,边部含有较高的Au,三者ω(Co)/ω(Ni)值绝大部分都大于1,指示其热液成因;从核部到幔部再到边部,Co、Ni含量逐渐降低,Se含量逐渐升高,说明其流体温度逐渐降低;黄铁矿中δ^(34)S值整体为-1.43‰~0.48‰,说明成矿物质主要来源于岩浆。黄铁矿的结构、微量元素特征、S同位素组成表明,驼路沟的成矿流体为富含Co、Ni、As等元素的低温热液流体。本研究对于揭示喷流热液型钴矿床成矿过程及指导类似矿床的找矿勘查具有重大意义。

萍乡市麻山钴矿成矿地质特征及矿床成因分析

萍乡市麻山钴矿是近几年发现的具有较大潜力的钴多金属矿床,区域上属萍乐坳陷带西段,具多层次大型构造叠加的成矿地质背景。经野外地质调查和钻孔验证,矿区发现厚大钴矿体,矿体视厚度为53.50 m,真厚度为34.39 m,平均Co品位为0.05%,最高Co品位为0.15%。矿体主要赋存在石炭系下统杨家源组与三叠系上统安源组的不整合面上的构造角砾岩及砂砾岩中。通过综合分析矿床成因,它为有构造破碎带热液环流蚀变参与的氧化淋滤沉积矿床。根据成矿地质特征,建立四位一体的成矿模型指导找矿,为该区找矿提供理论依据。

基于氧化物-金属多层膜固态化合方法制备MCNO薄膜

红外热成像技术具有高度实用性、灵敏性和可靠性等优点,在航空、医疗等多个领域发挥着重要作用。相较于其他类型的非制冷红外探测器,测微辐射热计(Microbolometer)具有工作范围宽、响应速率快且器件结构简单等优点。相较于非晶硅和氧化钒等常见热敏层材料,立方尖晶石结构的过渡金属氧化物锰钴镍氧化物(Mn-Co-Ni-O,MCNO)具有更高的TCR系数。使用磁控溅射法-电子束蒸发复合法在蓝宝石(Al_(2)O_(3))衬底上制备MCNO薄膜,结合XRD、SEM和电学性能测试,分析和探讨了工艺条件对其性能的影响。研究结果表明,在450℃沉积5 h得到厚度为450 nm的MCNO薄膜样品,随后在真空腔内原位退火1 h,再使用管式退火炉在空气氛围中进行60 min 850℃后退火,MCNO薄膜呈现出良好性能,(111)晶相的XRD半峰宽为0.48,晶格常数为8.71A(1A=10^(-10) m),晶粒平均大小为81.7±24 nm。使用四探针法测试MCNO薄膜室温下电阻率为642.19Ω·cm,室温下(295 K)电阻温度系数(Temperature Coefficient of Resistance,TCR)系数为-4.20%/K。在6~8.5μm波长范围内,最高吸光度为1.50。研究结果验证了所提出的多层复合方法用于制备MCNO薄膜的可行性,为进一步优化MCNO薄膜组份与掺杂配比以及结构-性能关系提供了新思路。

Synthesis and characterization of carbon-coated cobalt ferrite nanoparticles

Cobalt ferrite nanoparticles（CFNPs） were prepared via a reverse micelle method. The CFNPs were subsequently coated with carbon shells by means of thermal chemical vapor deposition（TCVD）. In this process, acetylene gas（C2H2） was used as a carbon source and the coating was carried out for 1, 2, or 3 h at 750℃. The Ar/C2H2 ratio was 10：1. Heating during the TCVD process resulted in a NP core size that approached 30 nm; the thickness of the shell was less than 10 nm. The composition, structure, and morphology of the fabricated composites were characterized using X-ray diffraction, simultaneous thermal analysis, transmission electron microscopy, high-resolution transmission electron microscopy, and selected-area diffraction. A vibrating sample magnetometer was used to survey the samples＇ magnetic properties. The deposited carbon shell substantially affected the growth and magnetic properties of the CFNPs. Micro-Raman spectroscopy was used to study the carbon coating and revealed that the deposited carbon comprised graphite, multiwalled carbon nanotubes, and diamond-like carbon. With an increase in coating time, the intensity ratio between the amorphous and ordered peaks in the Raman spectra decreased, which indicated an increase in crystallite size.

沉积岩-变沉积岩型钴矿研究进展与问题

沉积岩-变质型钴矿床占全球超过50%的钴资源储量,产量约占全球的65%以上,这类钴矿床主要分布在中非赞比亚-刚果(金)、美国爱达荷,及我国辽吉、山西、青海等地的沉积砂页岩、海底热水沉积岩及其变质岩系中。目前国际上对沉积岩-变沉积岩型钴矿的区域成矿地质背景、含矿建造、钴的赋存状态、后期变质与构造作用、成矿时代等方面有较多的研究,但在沉积-变质-热液改造等不同地质过程中钴的地球化学行为、沉积成矿条件与古海洋环境、钴的富集机理及其控制因素等方面的认识仍存在分歧和有待深入研究的问题。本文在综述国内外典型铜钴成矿带地质背景、含矿建造和矿床地质特征等的基础上,总结了各成矿带的主要成矿条件与成矿规律,分析了各矿带成矿流体和成矿物质的来源、富矿控制要素和成矿机制;提出控制钴沉积成矿的制约因素主要是大陆裂解、海洋氧化还原条件、沉积相与沉积环境等,而要形成富矿的关键是后期变质作用或热液活动的改造叠加。同时作者对全球沉积-变沉积型钴矿的时空分布规律及控制因素进行了探讨,提出今后应在古气候与古海洋环境、物质来源与矿源层、后期热液改造作用与钴元素超常富集成矿机理等方面开展详细和深入的研究。

东北地区富钴矿床成矿规律、成因类型与远景区预测

钴具有特殊的物理化学性质,被广泛用于现代尖端技术领域中,因而部分国家将其列入战略矿产资源清单。钴矿形成的独立矿床较少,以共伴生矿床为主。我国是一个钴资源相对贫乏的国度,资源保有程度严重不足。目前,在我国东北地区发现并勘探出具有一定规模的共伴生钴矿床,其中既有与Cu共伴生矿床,又有与Cu-Ni-Fe共伴生矿床。为此,需要进一步总结成矿地质特征,分析潜力,为今后地质找矿工作提供借鉴。本文从东北地区钴矿床分布和地质特征角度出发,初步厘定该区钴矿的矿床成因类型为沉积-变质型矿床、岩浆型矿床、海相火山沉积-变质型矿床和矽卡岩型矿床4类;其中,沉积-变质型和岩浆型矿床分布较广,主要产在古元古代辽吉裂谷区;结合典型矿床地质特征、区域地球化学和地球物理特征,进一步圈定了28个远景区,包括A类远景区4个,B类远景区8个,C类远景区16个。建议4个A类远景区作为将来找矿勘查部署中优先重点关注的地区。

准噶尔北缘成矿带蕴都卡拉钴矿成矿特征

钴是全球战略性关键矿产,对国民经济、国家安全和新兴产业发展具有关键作用。钴资源的国内供应基本来源于岩浆铜镍硫化物矿床冶炼铜镍的副产品,尚未发现独立钴矿床。准噶尔北缘成矿带蕴都卡拉钴矿,是除岩浆硫化物矿床类型之外的新发现。笔者通过蕴都卡拉钴矿成矿特征研究,初步认为钴矿聚集于闪长岩与玄武岩接触带的构造破碎带内,沿北西向断裂两侧分布,表现了钴、铜、金的典型组合,属于岩浆热液型矿床。在蕴都卡拉外围沿北西向断裂两侧发育多处闪长岩与玄武岩的接触部位,钴矿成矿条件优越,表现出较大的钴矿找矿潜力。笔者通过蕴都卡拉钴矿富集规律和成矿特征研究,旨在揭示钴矿产资源成矿潜力和找矿新靶区,支撑服务战略性矿产找矿行动,缓解中国钴矿产资源安全供应压力,降低安全风险。

Manipulating magnetic anisotropies of Co/MgO(001) ultrathin films via oblique deposition

We present a systematic investigation of magnetic anisotropy induced by oblique deposition of Co thin films on MgO（001） substrates by molecular beam epitaxy at different deposition angles,i.e.,0？,30？,45？,60？,and 75？with respect to the surface normal.Low energy electron diffraction（LEED）,surface magneto–optical Kerr effect（SMOKE）,and anisotropic magnetoresistance（AMR） setups were employed to investigate the magnetic properties of cobalt films.The values of in-plane uniaxial magnetic anisotropy（UMA） constant Ku and four-fold magnetocrystalline anisotropy constant K1 were derived from magnetic torque curves on the base of AMR results.It was found that the value of Ku increases with increasing deposition angle with respect to the surface normal,while the value of K_1 remains almost constant for all the samples.Furthermore,by using MOKE results,the Ku values of the films deposited obliquely were also derived from the magnetization curves along hard axis.The results of AMR method were then compared with that of hard axis fitting method（coherent rotation） and found that both methods have almost identical values of UMA constant for each sample.

Ore-forming material sources of the Baiyangping Cu-Co-Ag polymetallic deposit in the Lanping Basin,western Yunnan Province

The ore-forming material sources of the Baiyangping copper-cobalt-silver polymetallic deposit have been studied in view of the S, Pb, C, O and H isotopic characteristics and the ratio of Co/Ni of cobaltite. The results showed that sulfur in metallic sulfides may have come from a mixed sulfur-source consisting of the sulfur-source from metamorphic rocks in the basin basement with basic volcanic rocks and the sulfur-source from basin sulfates; lead in the ores was provided by the sedimentary rocks and basement rocks; CO2 in ore-forming fluids was derived from thermolysis of altered and normal marine facies carbonates and decarboxylation of sedimentary organic matter respectively; the ore-forming fluids belong to the SO4-Cl-Na-Ca-type basin thermal brines derived from paleo-meteoric waters; cobalt in the deposit may also be derived from the metamorphic rocks in the basin basement with basic volcanic rocks.